Symmetry oscillations sensitivity to SU(2)-symmetry breaking in quantum mixtures

TL;DR

This paper investigates how symmetry oscillations in one-dimensional bosonic quantum mixtures are affected by SU(2)-symmetry breaking, demonstrating their robustness across various interaction strengths and initial states.

Contribution

It shows that symmetry oscillations are robust in strongly interacting mixtures with arbitrary inter- and intra-species interactions, extending previous findings to more general conditions.

Findings

Symmetry oscillations persist under SU(2)-symmetry breaking.

The amplitude and frequency depend on the symmetry-breaking strength.

Population of initial states can vanish periodically, even in large systems.

Abstract

In one-dimensional bosonic quantum mixtures with SU(2)-symmetry breaking Hamiltonian, the dynamical evolution explores different particle exchange symmetry sectors. For the case of infinitely strong intra-species repulsion, the hallmark of such symmetry oscillations are time modulations of the momentum distribution [Phys. Rev. Lett. 133, 183402 (2024)], an observable routinely accessed in experiments with ultracold atoms. In this work we show that this phenomenon is robust in strongly interacting quantum mixtures with arbitrary inter-species to intra-species interaction strength ratio. Taking as initial state the ground state of the SU(2) symmetric Hamiltonian and time-evolving with the symmetry breaking Hamiltonian, we analyze how the amplitude and frequency of symmetry oscillations, and thus of the momentum distribution oscillations, depend on the strength of the symmetry-breaking perturbation. We find that the set of symmetry sectors which are coupled during the time evolution is dictated by the spin-flip symmetry of the initial state and show that the population of the initial state may vanish periodically, even in the thermodynamic limit, thus revealing the robustness and universality of the symmetry oscillations.